How are MTHFR and Langlebigkeit related?

The relationship between MTHFR and longevity is primarily mediated through homocysteine metabolism. The MTHFR gene encodes methylenetetrahydrofolate reductase, a key enzyme in folate and homocysteine pathways. The common C677T variant (rs1801133) reduces enzyme activity, leading to elevated homocysteine levels. Elevated homocysteine is an independent risk factor for cardiovascular disease, stroke, and cognitive decline – all of which can impact lifespan. However, the evidence is nuanced: the effect size of MTHFR variants on homocysteine is moderate, and the impact on longevity is modulated by diet (folate, vitamins B12, B6), lifestyle, and other genetic factors. Population studies show inconsistent results; some find a weak association between the TT genotype and increased mortality, while others do not. Moreover, adequate folate intake can attenuate the variant's effect. Thus, MTHFR is not a direct 'longevity gene' but a component in a multifactorial network. For individual health advice, testing MTHFR alone without homocysteine blood levels and lifestyle context is not clinically actionable. Evidence is based on observational studies, not randomized controlled trials. Caveat: No clinical prediction.